There are many ways to hang things on walls. Some make permanent holes in the wall, such as nails and tacks. Others rely on adhesive, but some adhesives used for hanging things damage the walls upon removal. More recently, adhesive hanging systems have been introduced that can be removed without damage to most wall surfaces, by progressively stretching the adhesive in a shear mode to detach a rigid hook hanger, for example, from the wall.
Some things hung on walls are flexible, such as posters and papers. Others, such as framed pictures and art, are rigid and present greater difficulties in removal if adhesively attached to walls, because they can not be flexed to peel them from the wall.
When using some hanging techniques, care must be taken to properly align and place the hanging components, so that the object being hung ends up level and at the desired height, for example.
Other systems for releasably hanging things, particularly rigid things, on surfaces such as walls, are sought.